Hartley



N. HARTLEY Re. 25,282

AUTOMATIC PROPORTIONER FOR FOUNDRY SAND MIXER Nov. 6, 1962 '7Sheets-Sheet 1 Original Filed March 29, 1952 I N V EN TOR. M62 5066957-45 y MAI-144,444

A T TOENEV5 N. HARTLEY Re. 25,282 AUTOMATIC PROPORTIONER FOR FOUNDRYSAND MIXER Nov. 6, 1962 7 Sheets-Sheet 2 Original Filed March 29, 1952IN VENTOR @M M y AM ATTORNEYS N. HARTLEY Re. 25,282 AUTOMATICPROPORTIONER FOR FOUNDRY SAND MIXER Nov. 6, 1962 '7 Sheets-Sheet 3Original Filed March 29, 1952 my 5 A w W v, m a E M W 9 F m A 5ATTORNEYS 1962 N. HARTLEY Re. 25,282

AUTOMATIC PROPORTIONER FOR FOUNDRY SAND MIXER Original Filed March 29,1952 '7 Sheets-Sheet 4 INVENTOR M; 90M 1 /418715) ATTORNEYS Nov. 6, 1962N. HARTLEY Re. 25,282

AUTOMATIC PROPORTIONER FOR FOUNDRY SAND MIXER Original Filed March 29,1952 '7' Sheets-Sheet 5 j I 1 I i /77 I f 14 L J INVENTOR I 4 450finer-45y F 1Z j fa ATTORNEYS N. HARTLEY Re. 25,282

AUTOMATIC PROPORTIONER FOR FOUNDRY SAND MIXER Nov. 6, 1962 7Sheets-Sheet 6 Original Filed March 29, 1952 Ai a iz wja ATTORNEYS Nov.6, 1962 N. HARTLEY 25,282

AUTOMATIC PROPORTIONER FOR FOUNDRY SAND MIXER Original Filed March 29,1952 7 Sheets-Sheet 'T INVENTOR N54 501v 64?.97'45 Y W r $4 M ATTORNEYSUnited States Patent 25,282 AUTOMATIC PROPORTIONER FOR FOUNDRY SANDMIXER Nelson Hartley, Baltimore, Md., assignor to Hartley ControlsCorporation, a corporation of Wisconsin Original No. 2,709,843, datedJune 7, 1955, Ser. No.

219,369. Mar. 29, 1952. Application for reissue Mar.

21, 1957, Ser. No. 647,735

46 Claims. (Cl. 22-89) Matter enclosed in heavy brackets appears in theoriginal patent but forms no part of this reissue s ecification; matterprinted in italics indicates the additions made by reissue.

This invention relates to a device and method for predeterminingquantities of ingredients according to diverse factors such as wetnessand temperature. The device is particularly adapted to supply Water andsand in automatically predetermined proportions to a foundry hand mixer.However, various alternative embodiments may be used for indicating theamount of water required to be added to a given batch of sand and cementand aggregate in making concrete, the determination being eitherindicated for a manually controlled mixing operation or used for theautomatic control of the mixing operation.

In foundry sand mixers, a predeterminable minimum quantity of Water mustordinarily be added to every batch of sand. If the water content of thereturned sand is reasonably constant, the additional water required,over and above a predetermined minimum, depends solely upon thetemperature of the sand in the batch. In my improved apparatus, Whilethe mixer is in operation on one batch, I am able to measure out thesand required for the next batch and also separately to measure and holdavailable for delivery to the mixer a quantity of water which includes,over and above the prescribed minimum, an amount of water which isautomatically related to the temperature of the measured batch of sand,the arrangement being such that the measured quantity of Water and themeasured batch of sand can be simultaneously dumped into the mixer.

If the water content of the returned sand is not substantially constant,I am able, in an alternative embodiment of the invention, to co-ordinatethe amount of added water to the original water content of the sand, aswell as to its temperature.

The used sand returned to the mixer may vary as much as 200" F. intemperature. It may also have wide variation in Water content, sincesome of the returned sand may never have been used to make a casting,and other parts of the returned sand may come from portions of the moldwhich were not close enough to the casting to have all the waterevaporate. My improved apparatus automatically responds to the sandtemperature and water content and sets the elements of an integratingdevice which controls the flow of water into a water measuring tank.When the flow reaches a value determined by the integrating device,further water flow is arrested.

In the drawings:

FIG. 1 is a view largely in front elevation and partially in sectionwhich diagrammatically shows the entire organization.

FIG. 2 is an enlarged detail view in vertical section through the watermeasuring tank and the discharge valve therefrom.

FIG. 3 is a view in front elevation on a reduced scale showing amodified water measuring tank arrangement, which makes a discharge valveunnecessary.

FIG. 4 is an enlargedview partially in front elevation Re. 25,282Reissued Nov. 6, 1962 and partially in transverse section through theintegrating device.

FIG. 5 is a view taken in horizontal section on the line 55 of FIG. 4.

PEG. 6 is a view taken in horizontal section On the line 66 of FIG. 4.

FIG. 7 is a view principally in front elevation and partially in sectionof the temperature responsive apparatus in the integrating device ofFIG. 4.

FIG. 8 is a View largely in front elevation and partially in section ofthe water volume responsive device in the integrating mechanism shown inFIG. 4.

FIG. 9 is a view in front elevation on a reduced scale showing thecontrol cabinet in which the integrating instrument of FIG. 4 isdesirably mounted.

FIG. 10 is a diagrammatic View partially in elevation and partially insection showing a modified arrangement in which the moisture of thereturning sand, as well as its temperature, determines the amount ofwater automatically added.

FIG. 11 is a view partially in side elevation and partially in sectionillustrating a train of driving connections used in the embodiment ofFIG. 10.

FIG. 12 is a detail plan view from the viewpoint indicated by the line1212 in FIG. 11.

FIG. 13 is a view taken on the line 1313 of FIG. 11.

PEG. 14 is a view taken on the line 1414 of FIG. 11.

FIG. 15 is a circuit diagram of the electrical connections used in theembodiment shown in FIGS. 10 to 13, inclusive.

FIG. 16 is a diagrammatic view partially in side elevation and partiallyin section showing a modified embodiment of the invention.

FIG. 17 is a diagrammatic view of a further modified embodiment of theinvention.

FIG. 18 is a diagrammatic view of another modified embodiment of theinvention.

Assuming that the device is to be used for the integrated measuring ofbatches of sand and water for delivery to a foundry sand mixer, aconventional mixer has been shown diagrammatically at 1-0 arranged fordischarge on to a conveyor 11. The mixer itself forms no part of thepresent invention. It is provided with a Water inlet at 12 and a sandreceiving hopper 13.

The previously used foundry sand, together with any increments requiredto make up losses, is stored in a storage bin 14, the discharge fromwhich is controlled by the valves 15 which are intergeared and operatedby a doubleacting pneumatic cylinder 16,. the piston rod 17 of which isconnected to one of the valves.

Arranged to receive the sand discharged past valves 15 from the storagebin 14 is the measuring hopper 18, which may discharge directly into thesand-receiving inlet 13 of the mixer, subject to the control of valves19 which are similar to valves 15, being intergeared and operated by thepiston rod 20 of a double acting pneumatic cylinder 21. The dischargeend of the storage bin 14 desirably extends into the measuring hopper 18so that the delivery of sand will automatically cease when the level ofthe sand 22 in the measuring hopper 18 reaches the outlet ofbin 14,regardless of the position of the valves 15.

The pneumatic actuating cylinders are supplied with air by means ofpipes 23, 24 which are oppositely connected to the respective ends ofthe cylinders 16 and 21 so that the valves 15 and 19 will work inalternation, valves 15 being open when valves 19 are closed, and viceversa. The pipes 23, 24 are connected with the air supply line 25, andalternatively with the vent 26 by means of a rotary valve 27 which isdiagrammatically shown in FIG. 1 and is manually operated, so that theoperator in charge of the mixer can deliver to the mixer, whenever it isempty,

a charge of sand 22 accumulated in the measuring hopper 18 while theprevious charge is being mixed.

The water required for the addition of said accumulated in the measuringhopper 18 is accumulated in the water measuring tank 38 from a watersupply line 31 controlled by an electromagnetically operated valve at32. A float 33 within the tank rises as the water enters the tank andcommunicates motion by means of rack 34 and pinion 35 through thebeveled gears 36, 37 and flexible shaft 38 to an integrating devicehereinafter to be described, whereby the flow of water is cut off whenan amount has been stored in tank 30 which is properly correlated withthe amount and temperature of the sand 22 in the measuring hopper 18.

When the air control valve 27 is manipulated to dump the sand, the wateris pneumatically released from tank 30 and dumped into the water inlet12 of the mixer 10. As shown in FIG. 2, this is accomplished byadmitting air pressure from pipe 23 through branch pipe 39 to the aircylinder 40 to lift the piston 41, the rod 42 of which lifts valve 43from its seat 44. The pins 45 with which the valve is provided, as shownin FIG. 2, are merely guides within the delivery pipe 46 to assure theproper resetting of the valve seat.

The large diameter of pipe 46 will be observed. I have found that if thewater is introduced in small volume into the mixer, the wet sand willtend to encrust the walls of the mixer, whereas if the entire volume ofwater is dumped into the mixer as rapidly as possible, the walls of themixer will tend to remain clean.

When all of the water and all of the sand has been discharged from tank30 and measuring hopper 18 into the mixer 10, the operator will reversethe position of valve 27 to admit air to the pipe 24, whereby valve 19will be closed and valve 15 opened. The air communicated through branchpipe 47 to the upper end of the air cylinder 40 will re-close the watervalve 43 in the water measuring tank 30.

FIG. 3 shows an alternative arrangement whereby no outlet valve on tank30' is required. The pipe 46' is provided with a gooseneck or trapwhich, at 48, is higher than the maximum level of water to be measuredin tank 30. Water will be held by gravity in the tank until the valve 27admits air from the pressure line 25 to pipe 23. Thereupon the admissionof such air through the branch pipe 39 to the interior of tank 30'creates a head upon the water in the tank which causes it to flow overthe gooseneck 48 and down through pipe 46 to the mixer 10. Thearrangement is regarded as equivalent to that shown in FIG. 1 and FIG. 2in that it releases the water into the mixer substantiallyco-incidentally with the release of sand, and uses pneumatic pressurefor that purpose.

The integrating apparatus now to be described measures the amount ofwater flowing into tank 30 to provide a primary amount which isindependent of sand temperature, and a secondary amount which isproportioned to sand temperature. In its preferred form, the apparatuscomprises a dial with pointers so that the operator can observe theoperation. The actual integration, however, is independent of the dialand of the pointers which are visible to the operator.

The instrument comprises a thermometer of the remote bulb type. The bulb50 is supported on a cross member 51 in the sand measuring hopper 18where it is exposed to the sand flowing into the hopper and to the sandwhich has accumulated therein. The bulb communicates through an armoredtube 52 with a Bourdon tube 53 in the instrument case 54 shown in FIGS.4 to 6. At the end of the Bourdon tube is an actuating arm 55 connectedby link 56 with a composite lever comprising parts 57 and 58, each ofwhich is pivoted on the pintle 59, the two parts being adjustablyconnected for calibration purposes by means of a bolt 60. The pivotalconnection between link 56 and lever element 57 is desirably madeadjustable also, the adjustment being provided by making the pivot bolt61 adjustable longitudinally of the lever in the slot 62.

The lever 57, 58 carries a segment 63 meshing with the pinion 64 on aquill shaft 65 which carries a pointer 66. The pointer 66 operates overa dial 67 which may be calibrated in terms of temperature. This is forthe benefit of the operator. The actual integration, however, isperformed by an integrating element which comprises a finger 70connected with the lever 57, 58 as shown in H68. 4, 6, 7 and 8.

The shaft 38 which is rotated by the movement of the float 33 within thewater measuring tank 30 drives within the meter casing 54 a worm shaft71 mounted in hearings in bracket 72 (FIG. 4) and carrying a worm 73 atits lower end. This worm meshes with the worm gear 74 mounted on a shaft75 which projects from the casing and is provided with a knob at 76.Within the casing it carries a pointer 77 movable over a dial 78 whichmay be calibrated in gallons. Immediately behind the pointer, the shaft75 is rotatably and slidably mounted in brackets 79, and at its rear endit is similarly mounted in hearing 81% fixed to the rear wall of themeter case. A compression spring 81 urges shaft 75 rearwardly in itsbearings. Between bearing and worm gear 74, this shaft carries a pinionat 82 meshing with a gear 83 which has an arm 84. This arm has a lostmotion connection with link 85 by means of a bearing pin 86screwthreaded into arm 84 and movably freely for the length of slot 87with which the link 85 is provided.

The link, when the pin 86 reaches the end of slot 87, transmits motionto a lever 88 pivoted on the rod 59 and supporting a sensitive switch at90 from which projects the oscillatory switch actuator 91 into the pathof movement of the finger 70. The switch contacts (not shown) of switch90 are normally closed and are opened by the actuator 91 when theactuator and the finger 70 are engaged as a result of the upwardmovement of the switch or the downward movement of the finger.

In order to give a visual indication of switch position, the lever 88has an extension 93 which carries a segment 94 meshing with the pinion95 on shaft 96. This shaft extends through the quill shaft 65 to thefront of dial 67, where it carries a pointer 98. The position in whichthe pointer 98 registers with pointer 66 is the position in which theengagement of finger 70 and switch actuator 91 opens the circuit throughswitch 90.

Connected to the terminals of switch 90, as shown in FIG. 4, areconductors 99 and 100. The wiring circuit is diagrammatically includedin FIG. 1.

In series in one side 101 of the line is the instrument switch 102, theopening of which opens the entire circuit. This switch connects withconductor leading to the microswitch 90 within the instrument case. Italso supplies through conductor 103 and conductor 104 a switch 105 whichis manually operable to permit the operator to add water withoutreference to the integrating device. Another branch of conductor 103leads via conductor 106 to the contact 107 of a relay which, whencontact 108 is closed by means of solenoid 109, serves to energize thecoil 110 of the electromagnetic valve 32, the return side of which isconnected through conductor 111 with the other side 112 of the line.

A branch conductor 113 leads from conductor 111 through a pneumaticpressure switch 115 to conductor 116. In series therewith is a resistor117 connected by conductor 118 with the filament 119 of an electronictube 120. The other side of filament 119 is connected by conductor 121with conductor 99 to be energized through the microswitch 90 in theinstrument casing. One of the plates 122 of tube is connected withconductor 121 by a branch conductor 123. The other plate 124 isconnected by conductor 125 with one of the contacts of the manuallyoperable switch 105 and also wtih the coil 109 which energizes the relayswitch 108, 107. The coil 109 5 is then connected by conductor 126 backto conductor 111 and to the return side 112 of the line.

It is the purpose of the :ctronic tube 120 to provide a controlled delayin the admission of water into tank 30, to ensure that the finger 711,comprising the integrating element actuated by thermostatic tube 50,will have time to reflect with accuracy the temperature of the sand 22in the measuring hopper 18. The operation is as follows:

The operator first sets the device to predetermine what amount of wateris to be added to a batch of sand regardless of temperature. Heindicates this amount of water by pulling forwardly on the knob 76 todisengage the worm gear 74 fro-m the worm 73. The length of pinion 82permits this pinion to slide freely in mesh with its driven gear 83.With the worm gear disengaged from the worm, the knob is used to rotateshaft 75 to move the pointer 77 over the dial 78 until it indicates onthe dial the number of gallons which are to be added regardless oftemperature. The knob is then pushed in to re-engage the worm gear withthe worm. The adjustment thus made will locate the driving pin 86 of thearm 84 on driven gear 83 at some intermediate point in the slot 87 asshown in FIG. 4. When the manually operable valve 27 is in the positionshown in FIG. 1, whereby pressure is admitted to the line 24, to admitsand from the storage bin 14 into the measuring hopper 22, the pressurecommunicated to the pressure switch 115 closes a circuit through suchswitch and resistor 117 and the filament 119 of electronic tube 120 andthence through the normally closed contact of switch 90 to the otherside of the line. The heating of filament 119 requires, in actualpractice, about a half a minute, thereby allowing plenty of time for thethermostatic bulb 50 to reach the temperature of the sand admitted tothe measuring hopper 18. The temperature of the sand, and the resultingresponse of the Bourdon tube 53 adjusts the lever 57, 58 and theintegrating finger 70 to a given position which is indicated on the dialby the pointer 66.

As soon as the filament 119 of tube 120 heats up, current flowingbetween the plate elements 122 and 124 of the tube will energize therelay coil 109 to contact 108 to contact 107, thereby providing a powercircuit to the coil 110 of the electromagnetic valve 32 to open suchvalve and allow the water to flow into the water measuring tank 31 Asthe tank fills, the motion of float 33 is communicated through theflexible shaft 38 to the instrument case where the worm 73 is rotated inmesh with worm gear 74 to move the pointer 77 back toward zero and torotate gear 83. Not until the pointer 77 reaches the zero mark, thusindicating that the entire primary quantity of water has been deliveredto the water measuring tank, is any motion communicated from the drivingpin 86 at the end of arm 84 to actuate link 85. Up to this point, thepin 86 has been moving idly in slot 87.

When the entire predetermined quantity of primary water has beendelivered into the tank, the pin 86 reaches the end of slot 87 and thelink 85 is actuated to tilt the lever 88 and thereby bodily to move theswitch 90. At the same time, the pointer 98 moves over the face of thedial toward registry with the temperature indicating pointer 66. Whenthe two pointers register, the finger '70 connected with the temperaturepointer will encounter the actuator 90 to connect with the link onswitch 90 and thereby with the water volume pointer. The engagement ofthe integrating elements comprising finger 7 and switch actuator 91opens the normally closed contacts of switch 90 to break the circuit tothe relay, whereupon the electromagnetic valve 32 closes to cut offfurther flow of water.

The operator now has at his disposal a measured batch of sand and abatch of water which has been accurately measured by the integratingmechanism above described, to be the correct amount to provide primarymoisture for 6 the sand and to provide secondary moisture in proportionto sand temperature, whatever that may be.

This eliminates the skill heretofore required to proportion water andsand for a foundry mixture and enables even an unskilled operator to mixsuccessive batches, regardless of sand temperature, to exactly therequired consistency.

Despite automatic temperature control of secondary water, the embodimentthus far described requires manual presetting to determine the amount ofprimary moisture to be added. Particularly in the event that themoisture content has material fluctuation, it is appropriate to set theprimary water supply automatically as suggested in FIG. 10 and otherviews presently to be described.

In the construction shown in FIGS. 10 to 15, inclusive, electrodes 13%,131 are mutually spaced in the batch hopper 18 and are so connected incircuit with an indicating device or devices, and a suitable supply ofcurrent, that the electrical resistance of the sand between theelectrodes will be measured as an index of its dryness. The wetter thesand, the greater will be its electrical conductivity and the smallerwill be the amount of primary water required. Therefore, the electricalresistance of the sand is used to predetermine that amount of waterwhich is supplied to the accumulating tank 30 prior to the addition ofsuch water as is used to compensate for high temperature. Referring tothe circuit diagram in FIG. 15, the secondary 132 of transformer 133 isconnected by lead 134 with electrode 130. The other terminal ofsecondary 132 is connected through rectifier 135 to a relay coil 136.This coil is in series with relay coils 137, 138, and 139, which aresimilar except that they are wound to attract the respective armatures140, 141, 142 and 143 at successively higher current flow. The conductor14-1 connects the seriesconnected relay coils to electrode 131 so thatwhen wet sand intervenes between electrodes 130 and 131 a circuit iscompleted from the secondary 132 of transformer 133 through the severalcoils.

When sufficient flow of current occurs to induce reaction of armature140, the movement of this armature toward the coil 136 closes thecircuit from the supply line 144 to contact 145, this being connected byconductor 146 to relay coil 147 and thence by conductor 148 to the otherside of the supply line 149. Energization of coil 147 attracts thesolenoid armature 150 into engagement with step 151 for actuation oflever 175 (FIG. 11) with results hereinafter to be described.

When the flow of current in electrodes 130 and 131 reaches a slightlyhigher value, such flow through the series connected coils 136, 137, 138and 139 will cause armature 141 to be attracted by coil 137. This willclose a circuit to contact 152 whereby in a manner similar to thatalready described, the relay coil 153 will be energized. In addition tolifting the armature 154 and step 155 of lever 175, such energizationwill cause an arm 156 of armature 154 to close a switch at 157 whichconnects-line 158 with the conductor 159 between relay coils 136 and137. The effect of this is to short therelay coil 136 out of thecircuit, leaving only coils 137,. 138, and 139 in series.

Similarly, a higher flow of current between the electrodes will causearmature 142 to respond to coil 138, thereby closing the circuit throughcontact 160 to relay coil 161 to attract the armature 162 to actuatestep 163 of lever 175. Armature 162, in responding to the energizationof its coil 161 closes a switch at 164 which shorts relay coil 137 outof the circuit, leaving only coils 138 and 139. Another arm 165 carriedby armature 162 closes a switch at 168 which acts as a holding circuitfor relay coil 161 to keep this coil energized even when coil 133becomes deenergized.

The fourth relay coil 139 has a resistance such that its armature 143 isthe last to be attracted. This armature does not respond during anynormal functioning of the device, but in the event of a short circuit,or the presence of water in amounts exceeding that which the apparatusis capable of handling, the flow of current between the electrodes willbecome high enough so that armature 143 will be attracted to engagecontact 170, thereby lighting the warning lamp 171. The several relaycoils 147, 153, and 161 also have telltale lights at 172, 173, and 174,respectively, to give visual indication to the operator that therespective coils are functioning.

As clearly shown in FIG. 13, which shows the position of the parts withall of the coils 147, 153, and 161 deenergized, the respective nuts 177,178, and 179 which are adjustable on the armature rods 150, 154, and162, are normally spaced at different distances below the steps 151,155, 163v of lever 175, thereby to provide different degrees of lostmotion in the operation of the lever. The nut 179 is virtually inengagement with step 163, while nut 178 is spaced below step 155, andnut 177 has increased spacing below step 151. Thus, when armature rod150 is elevated as shown in FIG. 14, it will actuate lever 175sufficiently to increase the spacing between nut 178 and step 155 toapproximately the same space which originally existed between nut 177and step 151. The space between nut 179 and step 163 now correspondssubstantially with the space between nut 178 and step 155 in theoriginal deenergized position of the parts.

When coil 153 is now energized, its armature bar 154 will engage step155 to raise it, and lever 175, to the dotted line positions of FIG. 14,thereby establishing full spacing between nut 179 and step 163. Thus thethree armature bars, all having identical strokes will, upon beingattracted by their respective solenoids, effect corresponding incrementsof travel of the lever 175, the lost motion compensating in each casefor the fact that the three armatures must act successively on the samelever.

As best shown in FIG. 11, the lever 175 has its initial positiondetermined by an adjustable stop 180 from which the lever is upwardlyoscillataole in the successive increments aforesaid about a pintle 182.Beyond the pintle, the lever is slotted at 183 for adjustment of pivotbolt 184 whereby link 185 is connected to lever 17 5. At its upper end,link 185 is connected by pivot bolt 186 with lever 841 which, instead ofbeing fixed to gear 83 like the arm 84 (FIG. 4), is pivoted to the gearupon pivot bolt 187. It will be remembered from the previous descriptionof the device shown in FIG. 4 that float operated driving connectionsrotate gear 74 and shaft 75, the latter carrying the pinion 82 shown inFIG. 12, as well as in FIG. 4 and FIG. 5. Thus, the oscillatory positionof the segment or gear 83 is a function of the amount of water in themeasuring tank 30. Assuming the lever 175 (FIG. 11) to be stationary,the rising of the float will transmit motion through pinion 82 and gear83 to lever 841 to effect the same movement of such lever as if thelever were fixed to the gear'83, as is lever arm 84 in FIG. 4. Themovement is the same because, in the assumed stationary position oflever 175, the pivot bolt 186 at the inner end of lever 841substantially coincides with the axis of the gear or segment 83. Thus,in the to and fro movement of gear or segment 83, motion is communicatedin the FIG. 11 device from the gear through lever 841 to link 851 tooscillate lever 88 and switch 90 exactly as previously described,movement also being communicated to the pointer 98.

The difference lies in the fact that whereas the gear 83 was, in thepreviously described construction, manually preset to determine theamount of primary water to be added, the presetting is now doneautomatically by the resistances and the electrical circuit abovedescribed, whereby the lever 175 is tilted from its deenergized positionof FIG. 12 to vary the position of lever 841 respecting gear 83, andthereby to vary the datum position of switch 90, lever 88, and pointer98. Ordinarily the resistance measuring circuit will have made theadjustment of the lever system preliminary to the introduction of waterinto the measuring tank 30 and the consequent response of the float andthe float operated gear 83. However, the integrating action of thedevice is such that it makes no difference whether the electrical systemfunctions prior to, or simultaneously with, the movement of gear 83; ineither case the position of pointer 98 and switch 48 will be a functionof the moisture that is in the sand and the water admitted to tank 30;and the efiect, as in the manually set device, is to determine theamount of primary water which is added prior to the addition ofsecondary water to compensate for sand temperature.

In the device shown in FIG. 4, the pivot bolt 86 is ad justable in slot87. In the present device, the pivot bolt 861 is not only adjustable inslot 871 of link 851, but also in the slot 842 of lever 841. This,together with the adjustment in radius of connection of link with lever175 provides very accurate control. Once the adjustment is determined,the device will accurately respond to water content of the sand toprovide for the desired primary water. To prevent overrun, due to theabrupt action of the solenoids on lever 175, it is desirable to controlthe movement of lever 175 with a dash pot 193, the plunger 194 of whichis connected by link 195 with lever 175.

Some of the features herein described are usable independently of othersand for different purposes within the contemplation of the invention. Assuggested in FIG. 16, the electrodes 13% and 131 may be used in a hopper200 which contains sand at 201 for delivery to a concrete mixer 292. Theelectrodes are connected in circuit with any suitable current source 283and a meter 264, the scale 285 of which may be calibrated in gallons.The position of the pointer 2.86 will be determined by the moisturealready present in the sand 281, the pointer moving counterclockwise inresponse to an increase of moisture from minimum to maximum. Thus,assuming the scale 205 to show an increase in gallons in a clockwisedirection, the effect of moisture already present in sand will be toreduce the reading on scale 285 of water to be added.

The operator can manually open and close the valve 207 to admit waterfrom supply pipe 288 to the concrete mixer 202 until the Water meter 289shows that the number of gallons added is the number of gallonsindicated by pointer 206 on scale 205, whereupon the operator will closevalve 207.

A similar principle of manual control may be used for integratingtemperature and initial water content as shown in FIG. 17, which may beassumed, for example, to be a foundry sand handling device. The hopper18 is identical with that of FIG. 10, having a thermostat 50 andelectrodes 130 and 131 and discharge valves 19. The thermostat 50connects with Bourdon tube 53, the arm 55 of which is connected by link56 with lever 570, as in FIG. 4. The segment 63 at the end of lever 578meshes with pinions 64 and 64' to oscillate dial 670, bearing a scalecalibrated in gallons or pounds. Pointer 66 is the indicating portion ofmilliammeter 210, which is connected in circuit between power source 203and electrodes 13% and 131, as above described. The arrangement is suchthat dial 678 oscillates counterclockwise in response to an increase intemperature of thermostat 50, and pointer 66 likewise oscillatescounterclockwise in response to an increase in current flow betweenelectrodes 130 and 131, consequent upon high moisture content of thesand in hopper 18. Thus a high moisture content in the sand will reducethe water requirement shown by pointer 66 and dial 670, whereas a hightemperature will tend to increase the water requirement shown by thecooperative action of the pointer and dial.

The operator manually controls valve 207 to deliver water from supplypipe 288 to an amount indicated by water meter 209, the water beingdelivered into a measuring tank 30 like that shown in FIG. 10 and FIG. 1and FIG. 2. However, the discharge valve 212 from tank 39 may, in thisinstance, be manually controlled.

FIG. 18 shows a modification which may be incorporated either in thedevice of FIG. 1 or that of FIG. 10.

Instead of measuring the water after it arrives in tank 30, it measuresthe water as it enters the tank by passing it through a meter 209', asin FIGS. 16 and 17. In this instance, however, instead of requiring theoperator to read the meter, the meter pointer shaft 215 is connected tothe flexible shaft 38 leading to the integrating device. With the meterset to zero at the commencement of each operation, it will be evidentthat when a required amount of water has passed through the meter intotank 30, the operation of the flexible shaft will out 01f the flow inthe same manner as if the flexible shaft were driven by the float typemeter 33, as above described.

While the completely automatic operation described in connection withFIGS. to 15, inclusive, and FIG. 18 is preferred, the devices of FIGS.16 and 17 will demonstrate the fact that the method involved may bepracticed manually if desired. It is further intended to demonstrate,with particular reference to FIG. 16, that portions or all of theapparatus are useful for purposes other than foundry sand handling, itbeing intended that the various mechanisms may be employed in anycombination for the handling of any appropriate material.

My improved method includes the measuring of the water content of sandas a guide to the amount of Water to be added thereto, whether the sandis to be used for foundry sand purposes or for concrete or for otherpurposes. Where foundry sand is involved, my method further contemplatesthe use of two separate factors in determining the amount of Water, thefirst being based on the water content already present in the sand andthe second being based on the temperature of the sand. If the watercontent of the returning sand is fairly constant, the primary water maybe added in fixed amount, the only variation being in the water whichcompensates for high temperature.

A further feature of the method invention, as applied to foundry sand,consists in the segregation of the measured water required for additionto a given batch of sand and the abrupt dumping of the measured batch ofwater abruptly into the mixture with the sand, as distinguished from theslow trickling of Water into previously present sand. As noted above, Iavoid incrustation of the mixer by accumulating the water in the processof measurement thereof and then dumping the measured batch of water intothe sand. A most important advantage in the abrupt introduction of wateris the immediate reduction of temperature of sand in the mix.

I claim:

1. In a device of the character described, the combination withmeasuring receptacles for first and second materials, of means fordischarging said materials from said receptacles, and means forintroducing into one of said receptacles a quantity of materialdependent upon a characteristic of the material in the other receptacleand comprising valve mechanism for cutting off flow to said onereceptacle, and operating means having integrating elements relativelymovable into mutual engagement, a measuring instrument responsive to thesaid characteristic of the material in the second receptacle andconnected to actuate one of said elements, and a quantity measuringinstrument responsive to the amount of material in the one receptacleand connected to operate the other of said elements, and means operativeupon the engagement of said elements to close said valve.

2. Means for measuring sand and water for subsequent mixing, said meanscomprising a sand container and a water container, a water sup-plyconnection to the water container provided with a control valve, athermometer exposed to the temperature of sand admitted to the sandcontainer, a Water measuring device operatively associated with saidwater container, and means for closing said valve comprising anintegrating device having integrating elements mounted for relativemovement into engagement with each other, and actuating connections toone of said elements from said thermometer and to the 10 other of saidelements from said measuring device, said integrating device havingvalve shutting connections operatlve upon engagement of said elements.

3. The device of claim 2 in which the actuating connections from saidmeasuring device to the other of said integrating elements include anadjustable lost motion device whereby a predetermined quantity of watermay be admitted before the last mentioned element is actuated.

4. A device for measuring a batch of sand and a proportionate batch ofwater, said device comprising a sand container, a thermometer exposed tothe temperature of sand therein, a water tank having a water supplyconnection and provided with an operatively associated Water measuringmeans and with a shut off valve, electromagnetic means for valveactuation, and an electromechanical integrating device including aswitch connected in circuit with said electromagnetic valve actuationmeans and comprising a first switch actuator connected with thethermometer to be driven thereby, and a second switch actuator connectedto be driven from said measuring means.

5. The device of claim 4 in further combination with means for passingthrough said water supply connection a predetermined quantity of waterindependently of control of said integrating device.

6. The device of claim 5 in which the means for passing said lastpredetermined quantity of water comprises a lost motion device in theconnection from said measuring means to the second integrating actuator.

7. The device of claim 5 in which the connections from said Watermeasuring means to the lost motion device include separable driving anddriven elements, the driven elements and said lost motion device beingmovable independently of the driving element when disconnected therefromto predetermine the amount of lost motion.

8. The combination with a sand measuring hopper and a water measuringtank, of manually operable means controlling the filling and emptying ofthe hopper and the tank, the means which comprises the tank fillingcontrol including a valve, a float in the tank, a thermometer in thehopper, integrating elements having motion transmitting connections fromthe float and the thermometer respectively and mounted from movementtoward mutual engagement, and a valve closing switch positioned to beactuated upon the engagement of said elements, the said valve having anelectromagnetic operator in operative connection to be controlled bysaid switch.

9. In a device of the character described, the combination with a sandhopper and a Water tank arranged for delivery to a foundry sand mixerand having delivery controlling means including a manually operablehandle movable between delivery and non-delivery positions, of a watersupply connection to the tank including a valve, a sand connection tothe hopper including a valve, means whereby the manipulation of thehandle to its non-delivery position efiects the opening of said valves,and means for closing the water valve including an electromagneticoperator therefor, an electric switch controlling said operator and anintegrating device comprising relatively movable integrating elements,one of which comprises an actuator for said switch, means mounting theswitch and said last mentioned element for bodily movement, a float inthe tank having motion tranmsitting connections to said switch for thebodily movement thereof, and a thermometer exposed to sand in saidhopper and having motion transmitting connections to the other of saidelements for the movement thereof, the engagement of said elementsserving to energize said electromagnetic operator to close said watervalve.

10. A device for measuring batches of sand and Water for delivery to afoundry sand mixer, said device having a sand hopper having inlet andoutlet valves connected for alternate opening movement and a waterreceptacle having discharge means connected to discharge Water to saidmixer coincidentally with the opening of the discharge valve or the sandhopper, a thermometer bulb exposed to sand in the hopper, a float in thewater receptacle, a pipe leading to the receptacle and provided with awater valve having an electromagnetic operator, a valve closing switchhaving an actuator and operatively connected to control said operator,means mounting said switch for bodily movement with its said actuator, amotion transmitting connection from said float to said switch for thebodily movement of the switch and actuator, an integrating element inthe path of movement of the actuator and also mounted for movement toand from the actuator, engagement of said element and actuator beingadapted to eflect operation of said switch, motion transmittingconnections from said bulb to said element for eiiecting the movement ofsaid element whereby to predetermine the point at which the element andactuator will engage for switch operation.

11. The device of claim in which one of said motion transmittingconnections is adjustable for predetermining the amount of relativemovement between said element and actuator which will occur prior tosuch engagement.

12. The device of claim 11 in which a second switching means in serieswith the switch aforesaid comprises a time delay relay havingconnections with the operator for said water valve to open the valve ata predetermined interval after the thermometer bulb is exposed to sand.

13. The device of claim 10 in which the respective motion transmittingconnections to said first switch and integrating element comprisepointers adapted to register upon engagement of said actuator and saidelement.

14. The combination with a sand hopper and a water tank having dischargevalves and filling valves, of means for opening the filling valve ofsaid hopper, inter-control means for initiating the opening of thefilling valve of said tank upon the opening of the filling valve of saidhopper, and means including an integrating device for independentlyclosing the filling valve of said tank, a thermometer exposed to thetemperature of sand in the hopper, a meter for measuring the liquid inthe tank, said integrating device comprising relatively movable andmutually engageable elements respectively provided with motiontransmitting connections from the thermometer and the meter, and meansoperative upon engagement of said elements to close the filling valve ofthe tank.

15. The device of claim 14 in which the motion transmitting connectionsfrom the meter to the integrating element actuated therefrom include anarm provided with a driving pin, a link having a slot in which said pinis movable, motion being transmitted to the last mentioned element whenthe pin reaches the end of the slot, and separable driving and drivenelements for actuating said arm, said arm and driven element beingmovable independently of the driving element, while the driving anddriven elements are separated, thereby permitting adjustment of the pinto a predetermined position in the slot, whereby a predetermined amountof water will pass said valve before said last mentioned integratingelement is operated.

16. The device of claim 14 in which the motion transmitting connectionsto one of said elements includes a lost motion device, a gear trainleading therefrom and having separable driving and driven members, thedriven member being movable independently of the driving member whenseparated therefrom, whereby to effect a preliminary adjustment of thelost motion device, and a pointer connected with the driven member ofthe gear train and provided with a scale over which the pointer isadjustable in the movement or" said driven member, whereby the extent ofindependent movement of the pointer is indicated.

17. The device of claim 16 wherein the separable driving and drivenelements comprise a worm and worm gear, the worm gear being mounted upona shaft provided with hearings in which it is axially movable as well asrotatable, and a pointer being carried by said shaft.

18. A device for measuring batches of sand and water for delivery to afoundry sand mixer comprising the combination with a sand hopper havinga discharge control valve and a valved means for supplying sand theretoin predetermined quantity, of a water tank, valve means for controllingthe discharge of water from said tank and provided with a common controlwith the means for controlling the discharge of sand from said hopper,said control being movable between discharge and non-dischargepositions, a water supply line leading to said tank and provided with avalve, means operative upon the movement of said control to itsnon-discharge position for opening said valve, and means including anintegrating device for closing said valve upon admission of apredetermined quantity of water to said tank, said integrating devicehaving relatively movable integrating elements adapted for engagement,means for closing the valve upon the engagement of said elements, awater measuring device provided with motion transmitting connections toone of said elements, and a thermometer exposed to the temperature ofsand in the hopper and provided with motion transmitting connections tothe other of said elements.

19. The device of claim 18 in which the means for opening said watersupply line valve is electromagnetic and includes a time delay relay,whereby the admission of water to said tank is deferred pending fullresponse of said thermometer.

20. The combination with a batch hopper for sand and a tank for water,of a pair of spaced electrodes in the batch hopper in a position to beexposed to sand therein, a pipe leading to said tank, anelectro-magnetically operabie valve controlling flow through said pipe,an electrical instrument and source of current supply connected incircuit with said electrodes for measuring electrical flow between theelectrodes through the sand, a water measuring device having a movableintegrating element connected to be operated therefrom, and a secondintegrating element connected with said electrical instrument, andmounted for movement thereby in opposition to the first element, saidintegrating elements having electrical contact means, saidelectromagnetic valve being connected in series with the contact meansof said elements to be closed by engagement of said element contactmeans upon the arrival in said tank or" an amount of water inverselyproportioned to the wetness of sand in said hopper.

21. In a device of the character described, the conbination with a sanddelivering hopper, of a sand d ampness meter, a water accumulating tankhaving a water supply pipe provided with a cutoff valve, a quantitymeter for water supplied to said tank, and integrating elementsconnected with the respective meters to be actuated thereby in oppositerelative directions, the element connected with the water meter beingmoved in a given direction in response to an increase in water in saidtank and the element connected with the wetness meter of the sand beingarranged to move oppositely to the said given direction when the wetnessof the sand is increased, electrical contacts carried by said elementsand adapted for engagement in the opposite movement of said elements,and electromagnetic means electrically connected with the contacts andconnected with the valve for closing the water supply valve upon suchengagement.

22. The combination with a water accumulating tank, a valve controlledpipe for supplying water thereto, and a meter for water so supplied, ofan integrating element mounted for movement and connected with saidmeter to be moved in a given direction according to the volume of Waterdelivered to said tank, a second integrating element movable inopposition to the first element, said elements having electricalcontacts engageable in the movement of said elements, a thermometerhaving a con nection to the second integrating element for movementthereof in the same given direction according to an increase intemperature to which said thermometer is subject, an electrical currentmeter having a connection to one of said elements, a pair of spacedelectrodes having a current supply connection in circuit with saidelectrical current meter, and a sand conduit in which said electrodesare exposed in mutually spaced relation as a means or" measuring thewetness of sand in said conduit, the connection of said electricalcurrent meter to the last mentioned integrating element being adapted tomove said element in a direction to advance it toward the otherintegrating element, whereby to reduce the interval between saidelements according to the wetness of sand in said conduit, and a valveclosing means pro vided with an operating circuit including andcontrolled by the contacts of said elements and operative uponengagement of said contacts to close said valve.

23. In a device for adding Water to foundry sand, an integratinginstrument comprising relatively movable integrating elements and aswitch having contacts actuated by said elements in the course ofrelative movement thereof in further combination with a sand hopper,measuring devices and a water accumulating tank, the said measuringdevices respectively comprising a sand wetness gage including electrodesspaced in the sand hopper, a sand thermometer having a temperatureresponsive bulb exposed to sand entering the sand hopper, and a Watermeter responsive to the water admitted to said tank, said tank having asupply pipe and a shutoff valve controlling the admission of water tosaid tank through said pipe, said valve having electromagneticallyoperable control means with circuit connections including said switchcontacts.

24. The combination with a sand hopper, of a moisture measuringinstrument exposed to sand therein, a temperature measuring instrumentexposed to sand therein, a first integrating element connected with thefirst instrument and mounted for movement in a given direction inaccordance with sand moisture increase, and a second integrating elementconnected with the second instrument and mounted for movement thereby inthe same given direction in the event of temperature increase, a watertank having an outlet for delivering water to the sand, a water pipeleading to the tank, a water supply valve in the pipe having anelectrically operative control means, and an operating circuit for saidcontrol means including a switch actuated by the engagement of saidelements.

25. The device of claim 24 in further combination with a rotatable dialperipherally provided with a scale graduated in terms of quantity ofWater and rotatably mounted in connection with one of said integratingelements, and a pointer cooperating With said scale and pivotallymounted in connection with the other of said elements.

26. In a device of the character described, the combination with afoundry sand feeder, of means for delivering Water to the sand inpredetermined relation to its existing moisture and comprising a watersuppy pipe with an electrically operable shut-elf valve and furthercomprising a water measuring device having a movable integratingelement, a moisture measuring device exposed to sand in the feeder andcomprising a second movable integrating element, the first and secondintegrating elements being mounted for relative movement toward mutualengagement in response, respectively, to water supplied and to increasedwater content in the sand, switch contact means operated by engagementof said elements, and a circuit including said contact means and saidelectrically operable shut-01f valve for cosing said valve when saidelements engage in consequence ofsaid. relative movement.

27. The combination with a water accumulating tank, a valve controlledpipe for supplying water thereto, and

a volumev responsive device for water so supplied, of an integratingdevice having linkage means mounted for movement and connected with saidvolume responsive device to be moved in a given direction according tothe volume of Water delivered to said tank, a second inte grating devicemovable in opposition to said first device, an electric switch devicehaving contacts, said first and second integrating devices beingarranged to jointly actuate said e'ectrical switch device, a thermometerhaving a connection to the second integrating device for movement insaid given direction according to an increase in temperature to whichsaid thermometer is subject, an electrical control means having aconnection to said linkage means, a pair of spaced electrodes having acurrent supply connection in circuit with said electrical control meansand a sand conduit in which said electrodes are exposed in mutuallyspaced relation as a means of measuring the wetness of sand in saidconduit, the connection of said electrical control means to said linkagemeans being adapted to move said first integrating device in a directionto advance it toward the other integrating device, whereby to reduce theinterval between said devices according to the wetness of sand in saidconduit, and a valve closing means provided with an operating circuitincluding and controlled by the contacts of said electrical switchdevice and operative upon engagement of said contacts to close saidvalve.

28. Equipment for controlling the quantity of liquid in a moist mixtureof solid material which comprises means for measuring the temperature ofthe solid material be ore addition of liquid including a first membermovable to a predetermined position in accordance with the temperatureof the solid material, means for measuring the percentage moisture inthe mixture including a second member movable to a predeterminedposition in accordance with the percentage of moisture in the mixture,and means comprising a third member operatively connected to both ofsaid first'and second members and jointly positioned thereby andresponsive to the position of said first and second member forcontrolling the addition of liquid to the mixture.

29. Equipment as defined in claim 28 in which said last means comprisesa switch actuator including said third member supported and positionedby both of said members, a switch actuated thereby, a solenoid valvecontro led by said switch between the source of liquid and the mixture,and an electric circuit connected to said solenoid valve and includingsaid switch.

30. Apparatus for producing a moistmixture of solid material comprisinga mixer, means for supplying such solid material to the mixer, a liquidsupply line leading to said mixer including a solenoid controlled valve,means for determining the percentage of moisture in said solid materialincluding a member movable in accordance with such percentage, acircui'tfor energizing the solenoid of said 'valve, and a switch inseries with said solenoid actuated by said member;

3]. In a device for adding water to foundry sand, relatively movableintegrating elements and a switch having contacts actuated by saidelements in the course of relalive movemeni thereof, a sand hopper, asand mixer into which said sand hopper discharges, measuring devices andwater supply means for supplying water to saidmixer, the s id measuringdevices comprising a sand wetness gage responsive to the moisturecontent of sand before final addition of water thereto, a sandtemperature measuring means responsive to the temperature of sandentering said hopper, said water supply means including a valve forcontrolling flow of water to be added to the sand in said mixer, saidvalve having electromagneticolly operable c ntrol means with circuitconnections including said switch contacts.

32. Apparatus for measuring and controlling the moisture content offoundry sand which comprises means for measuring the temperature of abatch of sand including a first element movable to difierent positionsin accordance with temperature of the sand, means for measuring themoisture content of the sand before final addition of water theretoincluding a second element movable to different positions in accordancewith the moisture content of said sand, water supply means for addingwater to the sand including a shut-ofi valve, a solenoid controllingsaid valve, a switch having contacts controlling said solenoid, andmeans operated as a consequence of the movement of said elements toactuate said contacts to close said valve when a quantity of watersufiicient to raise the moisture content of the sand to the requiredamount in view of its initial temperature has passed the valve.

33. Apparatus for preparing foundry sand for use comprising a sandhopper, a sand mixer in position to receive sand from said hopper, awater tank having a connection for discharging water into said mixer,temperature responsive means for measuring the temperature of sand insaid hopper and including a first element movable to different positionsin accordance with sand temperature, moisture responsive means formeasuring the moisture content of the sand before final addition ofwater thereto and including a second element movable to difierentpositions in accordance with moisture content of the sand, means forsupplying a first increment of water to be added to said mixerindependently of the temperature and moisture content of the sand, andmeans for controlling the supply of a final increment of water to beadded to the sand in said mixer comprising a solenoid operated valve, aswitch controlling said solenoid and switch actuating means includingsaid elements.

34. Apparatus for controlling the ultimate moisture content of foundrysand in accordance with its initial temperature and initial moisturecontent which comprises a sand mixer, temperature responsive meansresponsive to the temperature of sand, water supply means for addingwater to sand in the mixer, moisture responsive means responsive to themoisture of sand, and control means for said water supply meansresponsive jointly to sand tem' perature and sand moisture.

35. Apparatus for controlling the moisture content of foundry sand inaccordance with its initial temperature which comprises a sand mixer,temperature responsive means responsive to the temperature of sandentering said mixer, water supply means for adding water to sand in saidmixer, moisture responsive means responsive to the moisture content ofsaid sand before final addition of water thereto, and control means forsaid water supply means responsive jointly to said temperatureresponsive means and said moisture responsive means to limit theaddition of water to said mixture to that sufiicient to provide theproper sand moisture content as determined by initial sand temperature.

36. The combination with a sand hopper and a sand mixer into which thesand hopper discharges, of a moisture measuring instrument exposed tosand to be conditioned,

.a temperature measuring instrument exposed to sand to be conditioned, afirst integrating element connected with said first instrument andmounted for movement in accordance with an increase in sand moisture, asecond integrating element connected with the second instrument andmounted for movement thereby in accordance with sand temperature change,means for delivering water to said mixer including a water supply valvehaving an electrically operative control means, and an operating circuitfor said control means including a switch actuated by combined movementof said elements to close said valve when the quantity of water requiredto raise the moisture content of the sand in the mixer to a value asdetermined by sand temperature and initial sand moisture content haspassed said valve.

37. Means for preparing solid material and liquid for subsequent mixing,said means comprising a material container and a liquid s urce providedwith a control valve,

temperature sensing means exposed to the temperature of material in saidc ntazner, a moisture sensitive device exposed to the moisture ofmaterial in said container, means for actuating said valve comprising anintegrating device having cooperative integrating elements andconnections to ne of said elements from said temperature sensing meansand to the other f said elements fr m said moisture sensitive device.

38. A device for measuring a batch of sand and a proportionate batch ofwater, said device comprising a sand container, a thermometer meansexposed to the temperature of sand therein, a water supply connectionprovided with a water measuring means and with a shut ofi valve, meansfor valve actuation including an integrating device comprising a firstintegrating element connected with the thermometer means and responsivethereto, and a second integrating element responsive to said watermeasuring means, and an operating connection from the integrating deviceto the valve.

39. In a device of the character described, the combination with amixer, of a batch hopper and a water source having valve controlledmeans for discharge into the mixer, means for delivering from saidsource an amount of water proportioned to the amount of sand in thebatch hopper and automatically inversely proportioned to the wetness ofsand in the batch hopper, and means for concurrently delivering the sandand water respectively from the batch hopper and water source into themixer.

40. In a device of the character described, the combination withmeasuring receptacles for first and second materials, means fordischarging said materials from said receptacles, and means fordischarging from one of said receptacles a quantity of materialdependent upon a characteristic of the material in the other receptacleand cornprising valve mechanism for cutting ofl flow with respect tosaid one receptacle, and operating means having integrating elements, ameasuring instrument responsive to the said characteristic of thematerial in the second receptacle and connected to actuate one of saidelements, a quantity measuring instrument responsive to the amount ofmaterial in the one receptacle and connected to operate the other ofsaid elements, and means whereby the interaction of said elements closessaid valve.

41. The combination with a container for sand and a water source, of apair of spaced electrodes in the container in a position to be exposedto sand therein, a valve controlling flow from said water source, anelectrical instrument and source of current supply connected in circuitwith said electrodes for responding to electrical flow between theelectrodes through the sand, a water measuring device having anintegrating element connected to be operated therefrom, and a secondintegrating element connected with said electrical instrument, and meansfor actuating said valve in response to interaction of said integratingelements.

42. The combination with a water source, sand container means, and meansincluding a valve for adding water from said source to the sand, ofelectrical moisture probe contact means and thermometer means bothexposed to sand in the container means and means for actuating the valveand including an integrator having connections to the probe means andthe thermometer means for actuating the valve at a time such that thewater delivered through the valve will be related accurately to themoisture content and the temperature of the sand in the container means.

43. The combination with a source of water and sand container meansincluding a hopper and a mixer into which said hopper and water sourcehave discharge connections, of electrical moisture probe contact meansand thermometer means both exposed to sand in the sand container means,a valve for measuring water from said water source and means foractuating said valve and including an integrator having connections tothe probe means and the thermometer means for actuating the valve topass a measured quantity of water related accurately to the moisturecontent and the temperature of the sand in the sand container means.

44. Apparatus for controlling the quantity of liquid in a moist mixtureof solid material which comprises means for measuring the temperatureand liquid content of the material in advance of final addition ofliquid thereto, means for integrating said measurements and means foradding a quantity of liquid to the material according to saidintegration and which quantity is generally proportionate to materialtemperature as so measured and inversely proportionate to the liquidcontent of the material as so measured.

45. The apparatus of claim 44 in combination with means for mixing thematerial and the liquid so added.

46. The apparatus of claim 44 in which the means for adding liquid tothe material comprises a liquid line, a valve in said line and meanscontrolled by said integrating means to actuate said valve.

References Cited in the file of this patent 01' the original patent RobbMay 17, 1927 Bristol May 7, 1935 Irwin Dec. 20, 1938 Schlack Oct. 3,1939 Beardsley Dec. 2, 1941 McGillin Feb. 17, 1942 Jordan Feb. 3, 1948Riggen May 23, 1950 Van Ackeren June 6, 1950 Reilly Aug. 15, 1950Bessehnan et a1 Feb. 13, 1951 Harkenrider Mar. 6, 1951 Horth Apr. 17,1951 McIlvaine Apr. 15, 1952 FOREIGN PATENTS Great Britain Apr. 2, 1948Great Britain Apr. 5, 1949

